Of new cast addition Coleman, Moffat previously told Digital Spy: "She brings a kind of speed, a wit, a sort of unimpressed-ness which has the Doctor (Matt Smith) dancing a little harder than he's used to."

Fellow Who writer Tom MacRae also described the actress as "fantastic" in an interview with DS.

"She just had this amazing energy," said MacRae. "She's actually a couple of years older than Karen [Gillan] but she seems younger - she seems more of a teenager and bouncy."